Just how much can you follow the three laws
If I have a proper IDE and decent refactoring tools, then I really do prefer following the three laws strictly. Unfortunately, I have not as of 2008/10 found an IDE that has two particular refactorings/corrections for Ruby:
  • Create class missing at the cursor location (preferably in its own file)
  • Create method missing at the cursor location

I have these in C++, C#, Java, VB.Net and others. Since I don't have these, I'd consider relaxing the second rule of TDD to allow me to write an entire Example and then get add the missing Class/methods. I am not taking this approach in the tutorial because it doesn't add that much time and I'd rather you see how it is supposed to be practiced.

Is this realistic? Yes. Many developers better than I have practiced the three laws. In the simulator mentioned above, during the week I was there, we strictly followed TDD. I was not always at the keyboard but the work was being projected on an 1080i overhead projector so that kept the developers "honest."